Roll pass for rolling metal particles



Aug. 16, 1966 E. GEHRING 3,266,089

ROLL PASS FOR ROLLING METAL PARTICLES Filed Aug. 19, 1964 Fig. 1

United States Patent 3,266,089 ROLL PASS FOR ROLLING METAL PARTICLES Eckard Gehring, Dusseldorf-Kaiserswerth, Germany,

assignor to Schloemann Aktiengesellschaft, Dusseldorf, Germany Filed Aug. 19, 1964, Ser. No. 390,703 Claims priority, application Germany, Aug. 27, 1963, Sch 33,766 1 Claim. (Cl. 18-9) This invention relates to a roll pass or groove for the rolling of metal particles, such as powder or granules, more particularly into strips. The particles may in some instances include an admixture of non-metals. The invention consists in the feature that the roll-pass opening extends in the axial direction of the rolls. This method of constructing a roll pass is generally known in rolling-mill construction, but in the rolling of metal powder or the like, no use has hitherto been made of this known roll-pass construction, apparently on account of the fear of the formation of burrs or fins by so doing. In the rolling of metal particles, therefore, closed passes are employed in which the groove opening extends perpendicularly to the axial direction of the grooved rolls. In a known manner these roll-passes are obtained by the feature that in a roll constructed like a die there engages a second roll, constructed like a punch, so that the lateral boundaries of the grooves are formed by the die-like roll.

The rolling of metal particles into a solid strip or section requires very great roll pressures. These act not only perpendicularly to the axes of the rolls but also in the axial direction of the rolls. The die-like roll is thereby subjected to increased axial stress, owing to its walls or annular ledges that form the lateral boundary. This results in a widening of the roll-pass openings, directed perpendicularly to the roll axes, beyond the dimension conditioned by the finishing. Therefore even with the strictest finishing tolerances it is not possible to prevent the rolled stock penetrating into the roll-pass openings and occasioning a burr-formation on the rolled product, for instance a strip. The burr or fin extending perpendicularly to the surface of the strip may become jammed in the roll-pass opening between the rolls, and may thus lead to longitudinal cracks at the margin of the strip. Furthermore the strip admits but poorly of becoming extricated from the groove, above all when it remains sticking to the roll. Since moreover the strip leaves the rolling mill usually in an irregularly bent condition, it frequently becomes creased or kinked at the places where the up-sta-nding fin is interrupted.

With a view to obviating the formation of fins it has already been proposed to employ, instead of rolls of dielike and punch-like construction, ordinary smooth cylindrical rolls, at the ends of which, for the lateral bounding of the groove, rings or rolls are provided that can be put on by pressure. Even with a closed groove-formation of this nature, however, the formation of fins cannot be reliably prevented, so that the disturbing disadvantages of the formation of vertical fins are still liable to occur.

By the present invention, and employing, in place of closed grooves, open roll-passes with groove openings extending in the axial direction, fins extending in the plane of the sheet may in the best case be produced, which do not occasion a kinking of the strip, nor can they cause a poorer release from the groove, or a rupture of the margins of the strip.

In the case of particularly thin strips it is an advantage if the cross section of the strip is out only into one roll, and the co-acting roll is constructed as a normal smooth roll.

3,266,089 Patented August 16, 1966 In a further development of the invention, in order that no stock may pass outside the lateral boundary of the roll pass between the rolls, that is, into the roll-pass gap, which would unquestionably push the rolls asunder and thereby promote the formation of a fin, the stock is supplied in a reduced breadth, relatively to the breadth of the roll pass. In this case the supply breadth is so selected that owing to the spreading of the metal particles that occurs in the groove, the roll pass is completely filled up. This has at the same time the special advantage that the spreading pressure of the stock acting upon the lateral boundary of the roll pass is reduced to a minimum.

One constructional example of the invention is illustrated in the accompanying drawings, in which:

FIGURE 1 shows in section parts of a pair of rolls with stock between them; and

FIGURE 2 shows a plan view of the lower roll, with a feeding device.

1 and 2, in FIGURE 1, each denote one-half of a roll. In the periphery 3 of the roll 2 is cut a cross section 4 for the rolling of a sheet or strip. The peripheral surface 5 of the roll 1 is cylindrical, without any profiling, and forms the boundary of the roll pass in the direction of the roll axes 6. The lateral boundaries 7 and 8 are provided in the roll 2. If, owing to the application pressure between the two rolls being too small a roll-pass gap 9 is formed, into which stock can penetrate, a fin 10 is produced, which extends in the plane of the roll pass or in the plane of the sheet, but which cannot have any further disadvantageous effect upon the strip.

FIGURE 2 shows the roll 2, with a feeding device 11 for the metal particles 12. The boundary walls 13 and 14 of the feeding device for the stock 12 to be rolled are so arranged that the stock is not supplied in the full breadth b of the roll pass. The distance h between the two boundary walls 13 and 14 is so selected that the roll pass 4 is completely filled up by the spreading of the stock that takes place in the region 15 of the rolls. In this case metal particles cannot pass into a position between the rolls outside the roll pass 4 and push the rolls asunder.

I claim:

A roll pass for rolling metal particles, particularly powder and granules, into strips, comprising two co-acting rolls, and means for feeding metal particles to the roll pass, one of the rolls being a smooth cylindrical roll, and the other being formed with a roll-pass opening of the breadth, in the axial direction of the rolls, of the strip to be produced, and of a depth equal to the thickness of the strip to be produced, and the feeding means being adapted to feed particles to the roll pass over a breadth less than the breadth of the roll pass, but yet of such a breadth that owing to the spreading of the particles in the roll gap they will completely fill the roll pass.

References Cited by the Examiner UNITED STATES PATENTS 300,128 6/1884 Redeligx 18-11 343,523 6/1886 Lechler 18-9 1,073,381 9/1916 Wolle et al 25-75 XR 2,550,774 5/1957 Clem 29-111 2,922,223 1/ 1960 Boughton et a1 18-9 XR 2,987,778 I/ 1961 Worn.

FOREIGN PATENTS 373,441 4/ 1923 Germany,

4,788 of 1823 Great Britain.

WILLIAM J. STEPHENSON, Primary Examiner. 

